In this lesson, we will learn that capacitors in parallel add to the capacitance in the system in a similar way to placing resistors in series. You can use this knowledge to engineer a specific value of capacitance from those you already have on hand, or to increase the capacitance beyond that of your highest capacitor.
Total capacitance in parallel is simply the sum of the individual capacitances. (Again the “ … ” indicates the expression is valid for any number of capacitors connected in parallel.) So, for example, if the capacitors in the example above were connected in parallel, their capacitance would be
Capacitors are one of the most common circuit components. Why it’s important: Capacitors store electrical energy, and you can increase the capacitance of a system by placing capacitors in parallel. In this lesson, we will learn that capacitors in parallel add to the capacitance in the system in a similar way to placing resistors in series.
(a) Capacitors in parallel. Each is connected directly to the voltage source just as if it were all alone, and so the total capacitance in parallel is just the sum of the individual capacitances. (b) The equivalent capacitor has a larger plate area and can therefore hold more charge than the individual capacitors.
One important point to remember about parallel connected capacitor circuits, the total capacitance ( CT ) of any two or more capacitors connected together in parallel will always be GREATER than the value of the largest capacitor in the group as we are adding together values.
These two basic combinations, series and parallel, can also be used as part of more complex connections. Figure 8.3.1 8.3. 1 illustrates a series combination of three capacitors, arranged in a row within the circuit. As for any capacitor, the capacitance of the combination is related to both charge and voltage: